Comparison of high-flow nasal cannula and conventional nasal cannula during sedation for endoscopic submucosal dissection: a retrospective study

Background: The high-flow nasal cannula (HFNC) is a relatively recent method that provides high-flow, heated, humidified gas delivery. Objectives: We compared HFNC (group HF) and conventional nasal cannula (NC) (group CO) during deep sedation with propofol and remifentanil for endoscopic submucosal dissection (ESD). Design: Single-center, retrospective observational cohort study. Methods: In this study, a total of 159 cases were analyzed (group CO, 71 and group HF, 88). We collected the data from electronic medical records from September 2020 to June 2021. The lowest oxygen saturation (SpO₂), incidence of hypoxia (SpO₂ < 90%), rescue interventions, and adverse events between the two groups were investigated. Results: There were significant differences between the two groups in lowest SpO₂ and incidence of hypoxia [group CO versus group HF; 90.3 ± 9.7% versus 95.7 ± 9.0%, 25 (35.2%) versus 10 (11.4%); p < 0.001, p < 0.001; respectively]. Among the rescue interventions, the number of jaw thrust, patient stimulation, O₂ flow increase, and nasal airway insertion were significantly higher in the CO group than in the HF group. However, postprocedural chest X-ray showed higher rates of abnormal findings (atelectasis, aspiration, and pneumoperitoneum) in group HF than in group CO [group CO: 8 (11.3%) versus group HF: 26 (29.5%), p = 0.005]. In multivariable analysis, besides group CO, difficult type of lesion was the risk factor for hypoxia. Conclusions: Compared to the conventional NC, HFNC provided adequate oxygenation and a stable procedure without significant adverse events during sedation for ESD. However, caution is needed to avoid complications associated with deep sedation and difficult type of lesions.